Catalytic reaction of isobutane and propylene to produce lubricating oil



July 15, 1952 R l FRlTz 2,603,666

CATALYTIC REACTION'OF. ISOBUTANE AND PROPYLENE To PRODUCE LUBRICATING on. Filed sept. 21. 195o 5 ISObUTANE TAnmzEnz REO/CLE A E Pszobucv Rao/CLE ALcl SA-rulA-rl {55"150F.

Przopx/LENE FQ.E5H FEED @sabu-Uma) Patented July 15, 1,952

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' l'T' 4 PRODUCE LBRICATING' f on.;

l Rouge, hafr'asslgnor toe-j f ,A Stafda d. Dil `1;) velopment Gompanygacorpo-1,.; ,Y

vApplicaum september 21, 19250;lseriaiifzafitoge scieries. (c1. zsm-scars) This,l invention relates tothe production of a synthetic hydrocarbon lubricating' oil by the catalytic treatment of a mixture of propyleneand isobutane. f Y,

v lThis isa continuation-in-part of application Serial Number. 719.6972, nledJanuary l21, 19.47, and

.now abandoned.

It is well known thatV hydrocarbon oilsfof the lubricating-oil -range canV be produced by the catalytic polymerization of low molecular `weight olens, @An investigation of, thegproperties of products obtained bythe polymerization or pure feed.-v The proi'ufntion of theeproduet which i's oleflns of the C2 tov'Cis range, usingraluminum.

chloride as 1 the catalyst., was reported vinthearticleby Sullivan, Voorhees, Neelyfandvshankland .in Industrial `8:. EngineeringzChemistry, vol. 23, ppi; 604-'611:.(1931). Thehighestzyiscosity obtained amongithe series; of Lproducts was a, Viscosity of 201. seconds` Saybolt at 210f'Fninthe.

case ofupolymerof etene. The'viscosity indexv merely tend to make theproduct more viscous,V

of such productsl varied overa wide"rangeand'` v was` generally -quite low.` The polymer of propy1ene,'having a viscosityof. 'IO-se'condsfat 210- F., exhibited aviscosity index of only-20. A

It has beenfound,in accordance with the present invention, that a product of s considerably higher viscosity Vthan thatgenerally obtainable in thesimplepolymerization of oleins v'andfliavi'ng a very Ylow Conradsoncarbon' value andhigh flash point may b'e obtained bythey treatment 'of a mixture 'of isobutanev and propylene 'with aluminum' chloride under conditions whereby a large proportion of the normally liquid product is re-A cycled through thev reactor in contact with the catalyst. Thel product may,itherefore, be considered to be a good synthetic bright stock. The exact naturezof the reactionv which takes place is not known, but it is believed'l'fhat` the product consists largely of apolymer Aofpropylene, modifled in some manner bythe presence of the iso-l butane in the reactor. whereby the degree 'ofJ unsaturation is reduced and the product mademore stable. -p y The 'process' of this inventionk 'is'fcarried'l out 'in a continuousmanner by mixingi'sobutane and propyle'ne in the ratio of 4 to" molecularproportions ofthe former tol 1 molecular proportion of the latter, 'and this mixture 'is'passed into' a'Suit'- able reactor while maintaining a reaction temperature of about 60 to 90 F. and under a pressure sufcient to maintain a liquid phase reaction. The aluminum chloride catalyst may be simply dissolved in the liquid reactants or deposited on a suitable carrier. such as silica gel, activated alumina, Porocel, diatomaceous earth, and the recycled is such that lthe'volurn'e'iratio ofthe recycled product to the'i'ncomingI-fresh feed-'mixture is 4 -to v6 volumes-:ofthe formeinf preferably about 5 volumes', to 1 volume of l'the latter. IThe rateat' which the mixtureV offresh feed "and-recycle Vstool: isintroduce'dfinto the reactor is such that the contact time'for asinglevpass is from 5 to15 mnutes.- The contact time isnot critical as vtoV 'its upper limit, "since an increase intime*l will The unreacte'd isobutane.andother'light prod#- ucts which arenot desired 'inthe final product may be removed by `distillation'as'required.

In the accompanying drawing there is -shown anapparatus particularly suitable for conducting the process of v the present-invention. A fresh supply of isobutane in liquid form lis mixed withV any-recycle isobutaneavailable for use and passed through a pump. into anA 4 aluminum chloride saturator,` which isavessel containing aluminum chloride in powdered form and maini tained at a temperature preferably of the order of 125 to 150 -F.,'while the liquid'absorbs 'as much as possible of the 'aluminum chloride.` The isobutane .is subsequently blendedwith a supply of lliquid V,propyleneand `with Vthe recycled liquid products and then introduced into a soaking drum or reactor maintained at the. desired temperatura'ejg, 70 F., `this reactor being iilled with a solidabsor'bent"catalyst'carrier such 'as Porocel.` Aty theflower temperature.' or there@ actor *the aluminum chloride fis deposited on the' carrier. The rate offmovem'ent of the liquid' reactant through the reactor is adjusted vto 'provide for ther desiredcontacttime.` The products are passed from the upperportion of 'the' reactor through Va stabilizer', where the uniea'cted isobutane is removed as overhead and recycled for` further use, -A portion of 'thebottomsfrom the stabilizer `is `recycled, to `the reactor, in the" amount described above, while the portion not recycled is drawn off as the crude reaction product, which may then be further topped in a still (not shown) to produce an oil of the desired properties. In an obvious modification of this process a portion of the entire reaction product containing unreacted isobutane is recycled to the reactor, ac,-

merely as one illustration of the process of they? present invention and is net to .be construed 4 as limiting the scope of the in fanx'ltv ay."NY`

Example Liquid isobutane was passed through analu- Ininum chloride saturator'at.altemperature of` 135-150" F., then into a reactor containing Porocel, into which was also introducedastream of, liquid propylene and a stream of recycle'liquid" A products, the reaction taking place at '709 VF. The

isobutane and propylenef'were employed in a mol ratio =of L5/1; and Lth e, gy olume ratio of recycle productsitoatotal new ieedirwas A5/1.'Il1 e contact time: for. a, single 'passwas minutes and the operationxwas conducted al?, approximately 2 0() lbs. iper sd.; in. gaugepressure.- The liquid produotswere. .recycled; atten-removal Y01E; ilnreacted isobutane.by;"distillation, v jIhe portion of total liquid; productsnot lrecycled tothe reactor" was drawn o i and :this productfgwas found t0 represent .a 97 conversion-0f. thenropylel? employed and-was Vfurtlienfrac tionated into 01 a prodldence of cralg-ing was notiedwhenfthe oil was subjected to mme@ 'tembletatiilee 'I il@ insittt tions oil wellicht ellow ris/Q0@ Q11 te@ 'prov duCedareasfollows frnjmgni-asri' 'pointof' the product of the above 'xampl'ei's1-ain 'indicatio'ni of the 'stability offi 'the productg'andfa'jscope of` the'ASTM visg/tem'p.' chart 'and l'the viscosity indexl indicate the quality of the 'oil The very jloWConradson good stabiuty, f

It winv be undertooditnatvariati-ons Ain the properties of theproduct may be brought about by vvarying the conditions of the reaction some-v what, sincfejby operating at somewhat higher temperatures 'ai'lowerv 'viscosity' 'product will be formed. similarly a decrease intheg` contact time will, in general, reduce the molecular weight and viscosity of the product. What is claimed is:

l. A method of preparing a synthetic hydro-V carbon lubricating oil which compri-ses continu` .Ously Passinga mixture .vfg4 teffmolewlar pw-V portions ofiisobutane and 71.inolec'ul'a` proportion of propylene through a reactor in contact with an rf-aluminum chloride catalyst and simultaneously and continuously recycling a portion of the total normallyliquid '-r vaction product to said reactor,

' the volume rat o o`f recycled product, exclusive of any unreacted Aisobutane, -to the fresh feed 'mixture/@tering theY` reactor being 4-6/1, while mantaining0 n jthe reactor a temperature of apressure suiilcient to maintain a (s0-90 F; arid 1; liquid, 'phase freaction, and maintaining such a rate of flow through the reactor that the contact time is 5 to15 minutes.

2. A method according to claim 1 in which the molecular@ proportion2er isobutane to propylene in thefresh feed mixture is' Y5/1; and'in which the volumevratio of recycled product tov total vfresh feed isc/1. r '11" t. 3. ',Amethod according toclaim 2in whichjthe Contact time inthe 'reactor is 9minutes.' Y

4. 4A methodaccording to claim 3 temperature-in'thefreactor.is'70 F. Y The;4 method of' preparingl'a Asyntheti' hy drocarbonflubricating o'ill whichv comprises pass# ing liquid- J1isobutane through l an aluminum chloride .saturato-r.- atfa tempe'ratl'ireV of 13S-150 l.v andsubsequently; .intoafreactor` containing a solid yadsorbent catalyst carrier, .'andsimultaneously. p'assingxiliquidi propyleneinto. said reactor in the -proportionf-.of 1" molecular proportion vto 5 molecular.'y -proportibns .of 1.1 isobutane', .simultanea ously recycling.to saidzreactor, aportion yof thetotal nor mally fliquids'reacti'on product to said reaotonin theproportion of5 volumes of lrecycledpro duct:;to; lzvolume of to'tal isobutane-propylene feed; maintaining aitemperature :in said.` reactor of; F; andgaopressure sufficient to maintain a liquid phasef'freaction, :andmaintaining suchf a rate of iowthrough the reactor that the contact timeisabout9min-1.1t es.z v n. VA`(LLA methQd-accordingto claimg in which the unreacted Visobuta'ne is-separated by distillationy from the total reaction product before recycling= any portion ci the. reaction product to the reactor, a n d which the reaction is conducted Y Jan. 10,v 1950 Senn-12.1950

in whichfthel 1 -May. 10,- 1949V 

1. A METHOD OF PREPARING A SYNTHETIC HHDROCARBON LUBRICAING OIL WHICH COMPRISES CONTINUOUSLY PASSING A MIXTURE OF 4 TO 6 MOLECULAR PROPORTIONS OF ISOBUTANE AND 1 MOLECULAR PROPORTION OF PROPYLENE THROUGH A REACTOR IN CONTACT WITH AN ALUMINUM CHLORIDE CATALYST AND SIMULTANEOUSLY AND CONTINUOUSLY RECYCLING A PORTION OF THE TOTAL NORMALLY LIQUID REACTION PRODUCT TO SAID REACTOR, THE VOLUME RATIO OF RECYCLED PRODUCT, EXCLUSIVE OF ANY UNREACTED ISOBUTANE, TO THE FRESH FEED MIXTURE ENTERING THE REACTOR BEING 4-6/1, WHILE MAINTAINING IN THE REACTOR A TEMPERATURE OF 60-90* F. AND A PRESSURE SUFFICIENT TO MAINTAIN A 